Clean and wash Brussels sprouts and cook in salted boiling water for approx. 15-20 minutes.
Melt the butter in a saucepan, briefly sweat the flour and curry powder in it and deglaze with the broth. Add the crème fraîche, bring to the boil and season the sauce with lemon juice, salt, pepper and a pinch of sugar. Let simmer for 5 minutes. Wash and dice the apple and add to the sauce with the drained Brussels sprouts.
It goes well with pork tenderloin and jacket potatoes.
I took this recipe from a magazine about 15 years ago; it has been our classic for Brussels sprouts for all these years.